Foundation for roadways and other structures and method of making the same



Patented Mar. 19, 1929.

UNITED STATES PATENT QF'FICE.

SAMUEL S. SADTLER, OF SPRINGFIELD TOWNSHIP, KONTGGMEEY COUNTY, PENNSYIF VANIA, ASSIGNOR T AMIESITE ASPHALT CGMPANY OF JElMERICA, 43F CAMDEN, NEW JERSEY, A. CORPORATION OE NEW JERSEY.

FOUNDATION FOR ROADWAYS AND OTHER STRUCTURES AND METHOD 0] MAKING THE SAME.

No Drawing.

My invention relates to the making of solid foundations and more particularly to the making or roadways or other foundations where, for any reason, a standard cement and rock foundation is unnecessary, or the cost of. the same is not warranted.

The object of my invention is to produce a foundation structure in which the earth excavated for making a place for the foundation may be treated in such a manner as to render it suitable as a substantial part of the final foundation composition.

A further object of my invention is to utilize clayey earth as distinguished from sandy earth, and to treat it in such a manner as to make it available as the mineral content of road and similar foundations.

A further object of my invention is to subject to heat, earthy material which is not sandy and to which is added lime, either hydrated or caustic, and to agitate the materials while being heated and in such a manner that the resulting product is substantially homogeneous and suitable for the foundation of roads and other structures.

A further object of my invention is to make a strong, suitable, satisfactory foundation at a low cost and in Which the principal ingredient may be the very earth which was so excavated for the placement of the foundation.

Other objects of my invention will appear in the specification and claims below.

In carrying out my invention I prepare, preferably the excavated earth or soil by putting it into a boiler or digester, adding thereto, lime, either caustic or hydrated, in an amount dependent upon the plasticity of the 7 soil, and then heat the same in the presence of water or steam to a temperature of substantially from 75 to 100 (3., agitating or thoroughly stirring the ingredients while being heated so as to secure an intimate commingling and intermixture of the ingredients.

After the earth has been treated in this manner, the resulting composition is soft and readily spread but soon stifiens up considerably, although it does not set like Portland cement.

59 The apparatus which I may use in so treating clayey earths may be of any suitable character or description, but I prefer to employ.

one wherein a comparatively large cylinder,

Application filed larch 8, 1&26. Serial E0. 82,955.

boiler, digester or other hollow container is provided with a suitable manhole through which the material to be treated may be introduced therein and through which the treated material may also be discharged, and to employ such a cylinder or container as is mounted in suitable hearings or trunnions so as to be readily rotated in order that the material may be continually agitated or stirred during the treatment.

The apparatus also preferably embodies provisions whereby steam or hot Water or hot air may be introduced into the cylinder preferably at or near the trunnions so that after the material has been placed within the cylinder or receptacle for treatment, the manhole has been closed, steam or hot water or any other suitable heating agent may be introduced into or through the container or cylinder to heat the contents thereof up to a temperature of substantially 100 C.

in carrying out my invention as, for in stance, in constructing a road foundation, 1'

place Within the boiler, cylinder or digester a suitable amount of clayey soil, such as is usually excavated in the making of space for the placement of the foundation of a road, and to it I add lime, either caustic or hydrated, and in an amount de endent considerably upon the, plasticity of t 1e earth or soil. In order to give an adequate idea of the proportions of earth and lime which I employ in carrying out my invention, I will state that I generally use from 5% to 10% b Weight of lime to the weight of the dry soil Having put the soil and also a suitable amount of lime in the boiler or digester through the manhole, the manhole is closed and I then introduce into and through the digester, steam at a temperature of substantially 100 C. and I then rotate the cylinder or container continuously until the temperature of the contents thereof is substantially the same as that of the steam admitted, that is to say, until the temperature of the mass is substantially 100 C. After the contents have been thus heated and continually stirred, the pressure, if any, Within the cylinder or container is relieved, the manhole is opened, and the contents may be discharged therefrom and put in place Where the foundation for the road or other structure is to be laid. The material thus discharged from the apparatus is soft, is readily spread, but soon stiifens up without actually setting like Portland cement. In making, for instance, a roadway in a locality Where the soil is generally dry, this mixture of clayey earth and tion penetrates somewhat into the foundation, binds together the particles of the foundation near the surfa ce thereof and prevents the formation of dust on the road under traffic.

When, however, a more permanent and more water-resisting foundation is desired,

I may add to the mixture in the cylinder or container or'digester and after the temperature of the materials therein has been raised to the desired extent and the supply of heat has been cut-off therefrom, a certain amount of asphalt of suitable penetration and consistency. If the asphalt thus added to the material in the cylinder or digester or boiler is heavier than the contents of the digester, that is to say, if its specific gravity is greater than the contents of the digester and it sinks to the bottom of the mixture in the cylinder, I then also add a suitable quantity of a solvent ofasphalt, such as naphtha or petroleum, in order to make the asphaltlighter than the contents of the digester and more 'fluidQ After the asphalt and, if necessary, its solvent have been thus introduced into the digester or cylinder, the agitation of the contents thereof is resumed in order that the: asphalt may be thoroughly mixed and commingled with, and distributed throughout the contents of the digester after which the resulting composition is discharged through the manhole, and may be placed in position.

The asphalt in such cases is o erative to coat or cover some of the clay an sand particles of the resulting mixture but after the foundation thus made is in place a substantial amount of the asphalt rises to thesurface of the foundation as the foundation becomes.

dry and hardens, and the asphalt thus impregnates and coats the surface particles of the clay and lime of the foundation material.

The small amount of asphalt, which remains distributed throughout the body of the foundation, assists in making the foundation more water resistant, while the asphalt on the surface provides a suitable wearing surface for i the road.

' be rolled into the surface thereof, thereby providing a harder Wearing resisting nondusting surface than one in which such a surgester or cylinder.

face layer of small broken stone is omitted;

To make a firstclass, high grade road, a final surfacing of amiesite or other black wearing surface material maybe laid over the surface foundation in the usual manner.

In low places over a stretch of road such, for instance, as under railroad tracks, through marshy lands. and in depress ions in the roadway, it may be desirable to make the foundation more water-resisting, and for this purpose I may add some cement, as well as lime, to the earth being treated in the di- The amount of cement may yary considerably dependent upon the conditions to be met in a particular part of the road or locality but, generally speaking, to give the foundation a firm structure in the presence of water, I add to the earth substantially from 10% to 25% of cement, by Volume, in proportion to the volume of dry earth, and, in addition, from about 5% to 10% by Weight of lime.

The above process or manner in which the clayey earth may be treated may be varied somewhat from the method above described thus, for instance, after the earth has been placed in the cylinder 01' digester as above I described, I may add caustic lime and after closing the manhole, I may admit hot water at a temperature of substantially C. which water may be obtainable from the steam boiler of a steam roller or other apparatus usually used in the construction of roads, and then agitate the contents 'of the container. The caustic lime reacts violently 1 with hot water so admitted into, the cylinder or digester and, of course, evolves .a considerable amount of heat which, added to the for the purpose of heating the contents of the container to the desired temperature of substantially 100 C.

In whatever of the ways in which the earth is treated as above described, the resulting composition when discharged from the digester or container is thick but quite mobile,

I being preferably of about the consistency of thick freshly mixed concrete. It flows sl ght ly; is readily spread and after a short time stifl'ens or hardens to form a water-resisting 1 composition, and the water-resisting property of such foundation is-substantially increased when a relatively small amount of asphalt or when cement, or both have been added to the contents of the digester or cylinwill rise through the foundation mixture when placed and spread, and the amount of X moisture in the soil in Which the foundation is laid, more asphalt beingadded in moist lands and low places than in drier and higher localbe heated. If the temperature were above,

100 C. the Water contained in. the digester would be changed to steam which would pass off and thus reduce the amount of water in the digester, which is contrary to the operation desired. Steam or hot water, when the latter is employed, should be admitted at the boiling temperature of water, to wit, 100 (3., but since the temperature of the materials when introduced into the digester are much below 100 0. they will cool the steam or hot water and the resultin temperature of the mixture may be from C. to C. I therefore refer to the temperature as substantially or approximately 100 C. as definitive of the temperature of the materials when the heatin medium is introduced at a temperature o 100 C. although the temperature of the materials may be, in some instance, as low as 75 C. When the materials in the digester are heated anywhere from 75 to 100 (1., but not over 100 C., and in the manner above described, a foundation material having the characteristics above set forth will be produced.

Having thus described my invention, what I claim and desire to protectby Letters Patent of the United States is:

1. The method of making a road foundation which consists in adding to clayey earth, from 5% to 10% of the weight of said earth, of caustic lime, and water sufiicient to produce a mixture having a consistency similar to that of freshly mixed cement, heating the said mixture to a temperature of from sub-. stantially 75 to 100 C. and thoroughly agitating the mixture while being heated, and then placingthe mixture so treated on the roadbed as a road foundation course, and allowing it to dry and harden.

2. The method of making a road inclayey "soil, which consists in adding to the earth excavated for the placement of the foundation of the road from 5% to 10% of the weight of said earth of caustic lime, and water sulhcient to produce a mixture having substantially the consistency of freshly made cement, stirring constantly the mixture and heating the same to a temperature of from substantially 75 C. to 100 (1, adding to the heated mixture from to 2% of the combined weight of the earth, caustic lime and water, of an asphaltic material lighter than said mixture of earth, lime and water and thoroughly mixing said asphalt into and throughout the mass, then placing the slightly flowing readily spreading material so produced on the roadbed and allowing the same to dry and harden.

3.. The method of making a roadway in clayey soil, which consists in placing into a digester the earth removed for the placement of the foundation of the roadway, together with from 5% to 10% of the weight of the earth in the digester, of caustic lime, and water sulficient to produce a foundation material of substantially the consistency of freshly mixed cement, heating the same therein at a temperature of substantially from 75 to 100 C. and continually stirring the said materials together during said heating, putting into said digester from A;% to 2% of the weight of the contents of said digester, of an asphaltic material which is lighter than the heated contents of said digester, thoroughly mixing the said asphaltic material with and throughout the contents of the digester, and then spreading the material so treated on the roadbed and allowing the same to dry and harden, whereby a substantial amount of the asphaltic content of the material so laid rises to the surface of said foundation to form a surface of asphalt on said foundation, and part of said asphaltic content is distributed throughout said foundation course and increases the water-resisting properties thereof.

L The method of making a roadway in clayey soil, which consists in placing into a digester the earth removed for the placement of the foundation course of the roadway, together with from 5% to 10% of the weight of said earth, of caustic lime, and water, suflicient to produce a material having substantially the consistency of freshly mixed cement, heating the said ingredients together therein at a temperature of from substantially 75 C. to 100 (3., and continually stirring the said materials together during said heating, putting into said digester a small amount of asphaltic material of from substantially A;% to 2% of the weight of the contents of said digester, said asphaltic material being lighter than the heated contents of said digester, thoroughly mixing said asphaltic material with and throughout the contents of the digester, spreading the material so treated on the roadbed, sprinkling a thin la er of small crushed stone over the surface 0 the so placed foundation material, and rollin the said stone into the surface of. said foun dation material before said foundation material fully dries and hardens whereby a part of the asphaltic content of the foundation course so made rises to the to of said foundation course and forms with said small stones a wear-retion course, which consists in adding to a mass of clayey earth from 5% to of the weight of said earth of lime, and water suflicient to produce a mixture having substantially the consistency of freshly mixed cement, adding I thereto from substantially 10% to 25% of the volume of said earth of cement, thoroughly stirring said ingredients together at a temperature of from substantially 75 to 100 C., and thenlaying the material so produced as the foundation course of a road and allowing the same to dry and harden.

6. The. method of making a foundation material, which consists in adding to a clayey soil and water, from 5% to 10% of the weight of the said earth, of lime, and from 10% to of the volume of said earth, of cement, and water, suflicient to produce a mixture of said ingredients having substantially the consistency of freshly mixed cement, and thoroughly agitating and mixing the said ingredients together at a temperature of from 75 to 100 C. and then thoroughly mixing with said ingredients from substantially 5% to 2% of an asphaltic material which is lighter than that of the mixture to which it is so added. I

In witness whereof, I have hereunto set my hand this fourth day of March, 1926.

SAMUEL s. SADTLER. 

